Grinding machine table traverse mechanism



Nov. 11, 1941. J. R, WHITTLES 2,262,126

- GRINDING MACHINE TABLE TRAVERSE MECHANISM Filed April 20, 1939 5Sheets-Sheet l FIE-1 FIE-1D JQSEF'H H.WHITTLE5 m LAW Nov. 11, 1941.J.'R. WHITTLES 2,262,126

GRINDING MACHINE TABLE TRAVERSE MECHANISM Filed April 20, 1939 5Sheets-Sheet 2 llll JOSEPH R.WH:TTL..E5

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Nov; 11,' 1941.

Filed April 20, 1959 5 Sheets-Sheet 4 5 w 4 e T s z W .0. am e H m E w Ak. m .5 n R i v 51 I w): H 1 w j ml MW 0. E m as w m 5 am. .1 l w m r (L"m! .6 w ah l I In; u \vv. g

NOV. 11; 1941. J w 1 s 2,262,126

GRINDING MACHINE TABLE TRAVERSE MECHANISM Filed April 20, 1939 I 5Sheets-Sheet 5 JUSEFH RWH/TTLE5 .and automatically reciprocating thePatented Nov. 11, 1 941 GRINDING MACHINE TABLE TRAVERSE MECHANISM JosephR. Whittles, Holden, Mass., assignor to Norton Company, Worcester,Mass., a corporation or Massachusetts Application April 20, 1939, SerialNo. 268,870 6 Claims. (Cl. 60-52) The. invention relates to grindingmachines, and more particularly to a manually actuated and controlledhydraulic table traversing mechanism therefor.

One object of the invention is to provide a simple and thoroughlypractical grindingmachine table traversing mechanism. Another object ofthe invention is to providea manually controlled tabletraverse mechanismby which,

the table may be traversed easily without undue exertion on the part ofthe operator. Another object of the invention is to provide'a manuallycontrolled hydraulically operated table traversing mechanism.Anotherobject of the invemtion is to provide a manually controlledhydraulically actuated table traversing mechanism in which the speed ofmovement of the control member, such as the rotation of a hand Wheel,serves to control the rate of traversing movement of the table. Afurther object of the invention is to provide a manually operablehydraulic traverse mechanism which is so arranged and constructed thatrotation of the manually operable table traverse wheel serves to actuateand control the position of a hydraulic control valve to control thespeed of the traversing movement of the table. Other objects will be inpart obvious or in part pointed out hereinafter.

The invention accordingly consists in the features of construction,combinations elements,

and arrangements of parts, as will be exemplified f in the structure tobe hereinafter described, and the scope of the application of which willbe indicated in the following claims.

Inthe accompanying drawings in which is shown one oLvarious possibleembodiments of the mechanicalieatures of the invention,

, Fig. 1, is" ai'ront elevation of. a grinding machine embodying thisinvention; f Fig. 2 is a-i'ragmentary front elevation, on an.enlargedscale, of the'manual table traverse apron, having parts brokenaway to more clearly show the operating construction;

Fig. ,3 is a fragmentary vertical sectional view,

taken approximately on the line 3-3 of Fig. 2,

showing the manually operablecontrol valve for the traverse mechanism;Fig.;4 is a fragmentary piping diagram "of the fluid 'pressure systemfor manually traversing grinding machine table; I

Fig. 5 is a. fragmentary sectional view, taken approximately on the line55 of Fig. 3, showing the valve parts for admitting fluid to theleft-hand end chamber of the table cylinder;

Fig. 6 is a fragmentary sectional view, taken approximately on the line63 of Fig. 3;

' Fig. 7 is a fragmentary sectional view taken approximately on the line1-4 of Fig. 3, showing the valve parts for controlling the admission offluid to the right-hand end cylinder chambers;

Fig. 8 is a fragmentary sectional View, taken approximately on the line88 of Fig. 3, showing the exhaust passage of the manual control valveunit;

Fig. 9 is a fragmentary sectional View, taken approximately on the line9-99 of Fig. 2, showing the ports and valves for controlling the flow offluid to the table traversing cylinder;

Fig. 10 is a fragmentary sectional view, taken' 10-10 of Fig. 3.

approximately on the line showing the end thrust for the manuallyoperable control valve;

Fig. 11' is a fragmentary sectional view, taken approximately on theline il-ll of Fig. 10;

Fig. 12 is a fragmentary vertical sectional view through the stop andstart valve;

Fig. 13 is a fragmentary sectional view, taken approximately on the line|3l3 of Fig. 12, showing the valve for controlling the admission offluid to and from the table nism;

Fig. 14 is afragmentary sectional view, on an enlarged scale, throughthe table control valve; and

Fig. 15 is a diagrammatic illustration of the hydraulic control system.

A cylindrical grinding machine has been i1- lustrated in the drawingshaving a base which is provided with a transversely movable wheel slide2| which is movable-transversely on the usual V-way and hat Way (notshown). A rotatable grinding wheel 22 is mounted on a wheel spindle 23which is supported for rotation in bearings (not shown) on the wheelslide 2|. The grinding wheel 22 may be rotated by any suitable source ofpower either by means of a driving belt from an overhead countershaft,or it may be driven by an electric motor 24 mounted on the wheel slide2|. The motor 24 is provided with an armature shaft 25 which supports apulley 26. The pulley 26 is connected by a driving belt 21 with a pulley28 mounted on the outer end of the wheel spindle 23. Y

A work piece 30 is rotatably supported on a headstock center 3| carriedby a headstock 32. The other end of the work piece 30 is supported by afootstock center 33 carried by a rootstock 34. The headstock 32 andfootstock 34 are mounted on a longitudinally reciprocable tabletraversing mecha- 35 which slides longitudinally on a flat way and aV-way (not shown) on the base 29.

The grinding wheel slide 2| is arranged for a transverse feedingmovement to cause the grinding wheel 22 to approach or recede from thework piece 39 so as to grind the same to the desired extent. A wheelfeeding mechanism is provided comprising the well known half nut androtatable cross feed screw (not shown) which are actuated by a manuallyoperable feed wheel 49 which is rotatably supported on the front of themachine base. The feeding wheel 49 is provided with a micrometeradjusting mechanism 4|, and is arranged to be rotated either manually orautomatically by means of a reciprocable picker or ratchet pawl 42.- Thedetails of the grinding wheel feeding mechanism have not beenillustrated in the present case, since .they are not considered to be apart of the present invention. The wheel feeding mechanism utilized is awell known wheel feeding mechanism such as, for example, that shown inthe prior U. S. patent to C. H. Norton No. '762,838 dated June 14, 1994.For further details of the wheel feeding mechanism, reference may be hadto the above-mentioned patent. In a cylinder grinding machine, it isdesirabl to provide a power operated traversing or reciprocatingmechanism to cause a relative longitudinal traversing movement betweenthe rotatable work piece 39 and the rotatable grinding wheel 22 so as togrind the work piece to the required cylindrical form. A fluid pressureoperated traversing mechanism is provided comprising a fluid pressurecylinder 59 which is flxedly mounted to the base 29 of the machine. Apiston is slidably mounted within the cylinder 50 and is provided with adouble end piston rod 52' which extends through the opposite ends of thecylinder 59 and is fastened to brackets 53 and 54Which depend from theopposite ends of the longitudinally movable work supporting table 35.The brackets 53 and 54 are either formed integral therewith or rigidlyfixed to the under side of the table 35. A control or reversing valve 55is provided to control the direction of movement of the piston 5| andthe table 35. The valve '55 is preferably of a piston type compris- 'inga valve stem 56 having valve pistons 51, 58

and 59 integrally formed therewith.

A fluid reservoir 69 is located preferably within the base 29 of themachine. Fluid is pumped from the reservoir 69, through a pipe 6|, bymeans of a motor driven fluid pressure pump 62, and is forced through apipe 63, a pipe 64, a pipe I86, and through port 66; respectively, inthe control valve 55. As shown in the position of movement of the table35.

the parts illustrated in Fig. 15, fluid under pressure passing throughthe pipe 64, the pipes or passages I86 and I81, and the port 66 enters avalve chamber 61 located between the valve pistons 58 and 59 and passesoutwardly-through a port 68 and a pipe or passage 69 into a cylinderchamber 19 to cause the piston 5| and table 35 to move in a directiontoward the left (Figs. 1 and 15). During the movement of the piston 5|and the table 35 toward the left, fluid is ex- 1) so as to reverse theflow of fluid pressure to and from the cylinder 59. In this position ofthe valve, fluid under pressure passing through the pipe 63, the pipes64 and I86, and the port 65 enters the valve chamber 14 between thevalve pistons 51 and 58 and passes outwardly through the port 13, thepipe 12, into the cylinder chamber H, to move the piston 5| and table 35toward the right, as viewed in Fig. 1. movement of the table, fluidwithin the cylinder chamber 19 is exhausted through the pipe or passage69, the port 68, into the valve chamber 61, and out through the port 15,the pipe or passage 15a, and the pipe 16, into the reservoir 69. I v

The reverse or control valve 55 is preferably actuated automatically intimed relation with the movement of the work table 35. A reversing lever89 is pivotally mounted on a stud 8| and its upper end is arranged inthe path of adjustable-dogs 82 and 83 carried by the table 35. Thereversing lever 89 is operatively connected to shift the reversing-valve55 in the desired timed relationship with the reciprocation of the table35. In order to control the speed or rate of movement and to start andstop the movement of the reciprocable work table 35, a combined. speedcontrol and start and stop valve 99 is pro--' vided. The valve 99 ispreferably arranged in the exhaust side of the fluid pressure system sothat fluid under pressure exhausting from the cylinder 59 is throttledto control the speed. of

I The valve 99 is preferably of a piston type having a slidably mountedpiston 9| within the-valve casing 99. The valve piston 9| is providedwith a V-shaped passage or groove 92 which is arranged to open or closea port 93 in the exhaust pipe 16 so as to stop or start the flow offluid in the table traversing mechanism or, when rotated in an openposition, the V-shaped passage 92 serves to vary the size of theaperture between the V- shaped passage 92 and the port 93 so that thetraversing speed of the table 35 may be readily varied as desired. Inthe full-line position (Fig. 12), the valve piston 9| is in an operatingposition, with the port 93 partially uncovered.

A serrated portion 96 formed on the valve stem 91 cooperates with aspring-pressed plunger 98- to maintain the valve piston 9| in thedesired rotary position. Due to the fact that the grooves of theserrated portion are arranged parallel to the axis of the valve, thevalve piston 9|, may be moved endwise from a stop to a start or from astart to a stop position without changing the rotary position of theV-shaped groove 92 of the piston 9|. The valve stem 91 is journalled ina bearing block I99 and a manually operable control knob I9I is mountedon the outer end of the valve stem 91 to facilitate a rotary adjustmentof the valve to produce the desired speed.

In order to move the valve piston 9| from a start to a stop orfrom astop to a start position, a manually operable control lever I92 ispivotally mounted on a stud I93 supported in a bracket I94 projectingfrom the front of the machine base 29: The lever I92 is provided withdiametrically opposed pins I95 which ride in slots I96 on opposite sidesof the bearing member I99 (only one of the pins and slots being shown inthe drawings). The pins I95 and slots I96 facilitate endwise movement ofthe valve piston 9| and also permit a rotary adjustment of the piston 9|to control the speed of movement of the table 35. To stop the exhaust ofDuring this fluid from the system so as to stop the movement of thetable 35, the manually operable control lever I02 is moved into aposition I02a (Fig. 12) which shifts the control valve piston 9| so thatthe V-shaped groove 92 is in position 92a, thereby closing the port 93and preventing further exhaust of fluid from the system.

To attain the main object of the invention, a manually controlled tabletraversing mechanism is provided whereby the table 35 may be traversedlongitudinally without undue effort on the part of the operator. Amanually controlled hydraulically actuated table traversing mechanism isprovided in which the speed of movement of a control member, such as therotation of a manually operable hand traverse wheel, serves to controlthe rate of traversing movement of the table 35.

As illustrated in the drawings, a manually operable hydraulic traversecontrol apron H is mounted on the front of the machine base 20. Thetraverse apron H0 is provided with a rotatable shaft 1 II which isjournalled in bearings H2 and H3 within the apron H0. The shaft IIIserves as a support for a rotatable valve member H4. A rotary valvemember H5 surrounds the valve member H4 and is rotatably supportedthereon. In order to provide an accurate bearing support for therotatable valve member H5, a bushing or sleeve A is fixedly supported inthe casing or apron I I0. The rotatable valve member H4 is supported bya bushing or sleeve B which is fixedly mounted in the casing or apron H0and a bushing C which is fixedly mounted within a central aperture inthe rotatable valve member H5. A gear H6 is formed integral with theouter rotary valve member H5. The gear H6 meshes with a gear IIIrotatably supported on a stud H8. A gear H9 is either formed integralwith or fixedly mounted to rotate with thegear H1. The gear H9 mesheswith a gear or pinion I20 which is supported on the inner end of arotatable shaft I2I. The shaft I2I is journalled in a bearing I22 formedin a cover plate I23 on the front of the apron I I0. A manually operabletraverse control wheel I24 is fixedly mounted on the outer end oftheshaft I2I.

The shaft I I I is preferably arranged so that it may be clutched torotate with the rotary valve member H4 or may be declutched therefromand rotated continuously while the valve member H4 remains stationary. Acone-shaped clutch member I 21 is keyed to a reduced end portion I28 ofthe shaft II I. An internal frusto-conical clutch member I29 is formedintegral with the rotary valve member H4. A compression spring I30surrounding the shaft III and interposed between the clutch member I21and a recessed portion of the valve member H4 serves normally to holdthe clutch parts disengaged. The rotary valve member H4 is arranged sothat it may have an endwise or axial motion sufficient to engage ordisengage the clutch.

In order to engage the clutch member I29 with the clutch member I21, afluid pressure mechanism is provided. A fluid pressure operated pistonI3I, which is slidably mounted within the sleeve or bushing B, is formedintegral with the rotatable shaft III. When fluid under pressure isadmitted through a pipe I90 and an intake port I32 to the valve apron,it passes around an annular groove I33 surrounding the periphery of therotary valve member H4 and passes through a radially extending passaginto a longitudinally extending passage I34 which is formed within thevalve member H4 and extends in a direction substantially parallel to theaxis of retation thereof. Fluid under pressure within the passage I34enters a cylinder chamber I35 formed between the piston I3I and theright-hand end face of the valve member H4 (Fig. 3), which pressureserves to move the rotary valve member H4 towards the left (Fig. 3)against the compression of the spring I30 so that the clutch member I29drivingly engages the clutch member I21. When fluid under pressure iscut off from the port I32 in the valve apron H0, the releasedcompression of the spring I30 moves the valve member H4 toward the right(Fig. 3) a sufficient distance to disengage the clutch member I29 fromthe clutch member I21. I

The port at the end of the passage I89 in valve I is elongated (Fig. 13)and the port I92"is similarly elongated so that in the position of thevalve I80, as shown in Fig. 13, that is, when the valve I80 ispositioned for a hydraulic power traversing movement of the table, fluidmay exhaust through the pipe I into the valve chamber located betweenthe valve pistons I82 and I83 and pass outwardly through pipe I93 intothe reservoir 60. The exhausting of fluid through the pipe I90 combinedwith the released compression of the spring I30 serves to cause thepiston H4 to move toward the right (Fig. 3) to disengage the clutchsurfaces I2II29.

The inner end or right-hand end' (Fig. 3) of the shaft I II is providedwith a gear I38 which is keyed thereto and meshes with a rack bar I39depending from the under side of the table .35. When the table 35 isreciprocated longitudinally by means of the fluid pressure piston 5I andcylinder 50,'the clutch I21'-I29 is disengaged, thus allowing the gearI38 and shaft III to rotate through the rack bar I39 without rotatablyshifting the position of the valve H4.

Fluid under pressure entering the longitudinally extending passage I34in the valve member H4 may pass outwardly in a radial direction througha radially extending passage I40. The valve member H4 is rotated in acounterclockwise direction (Fig. 5) until'the V-port I40a uncovers aport or passage I4Ia within the rotary valve member H5 so as to admitfluid under pressure to an annular groove I4I formed in the outerperiphery of the valve member I I5. The annular groove I is arranged toadmit fluid through a radially extending passage |42a into alongitudinally extending passage I42 (Fig. 5) which passes fluid underpressure to open a valve I43 against the compression of a spring I43a soas to pass fluid under pressure through a port I44 and a pipe I45 topipe I2 and thence to the cylinder chamber 'H formed between theleft-hand end of the cylinder 50 and the piston 5|.

Similarly, fluid within the passage I34 may pass through a radiallyextending passage I50 within the valve member H4. The valve member H4 isrotated in a clockwise direction (Fig. '7) until the V-port I 5Iuncovers a port or passage I52 within the rotary valve member H5 so asto admit fluid under pressure to an annular groove I 53 formed in theouter periphery of the valve member I I5. The annular groove I53 isarranged to admit fluid through a radially extending passage I54 into alongitudinally extending passage I55 (Fig. 7) which passes fluid underpressure to open a valve I56 against the compression of a spring I5! soas to pass fluid under pressure through a port I58 and a pipe I59 topipe 69 and thence to the cylinder chamber 10 formed between theright-hand cylinder head of the cylinder 50 and the piston I.

In order to maintain' the valve members H4 and H5 in proper timedrelationship with each other during hydraulic reciprocation of the table35 when clutch means I21, I29 are disengaged, the inner rotary valvemember I I4 is held against rotation relative to the outer rotary valvemember I I5 during the hydraulic reciprocation of the table 35. This ispreferably accomplished by an end thrust washer I60 and a plurality,namely four, of symmetrically arranged springs I 6I (Figs. and 11) whichare supported in apertures I62 within the table traverse apron IIO'andwhich are arranged to exert an endwise pressure toward the left (Fig. 3)on the outer rotary valve member II5 so that the left-hand recessed endface of the valve member II5 frictionally engages the right-handend'face of a flange I63 formed in-.-

tegral with the inner rotary valve member II4, so that if the manuallyoperable hand wheel I24 is accidentally rotated while the table 35 isbeing reciprocated by the power operated fluid pressure mechanism, therotary valve members H4 and I I5 will be maintained in timedrelationship with each other. The compression of the springs I6I issomewhat less than the compression of the spring I30, so that therotatable valve members H4 and H5 may be held frictionally in apredetermined relationship with each other while at the same time thecompression of the spring I30 holds the clutch means I21, I29disengaged.

It will be readily apparent from the foregoing disclosure that with asingle passage through the valve member II5 to each of the peripheralgrooves MI and I53, it will only be necessary to rotate the valve memberone-third of one complete rotation or less before the inlet of fluidpressure is conveyed to start the table movement in either direction. Aspreviously described, the compression springs I6I bearing against thethrust washer I60 normally tend to hold the valve member H5 infrictional engagement with the valve member I I4 during the hydraulictraverse of the table so that these two rotary valve parts aremaintained in the operating position shown in Figs. 5 and 7 with theV-ports I40a and I5I located substantially midway between the radialpassages I4Ia and I52 so that only a slight device to prevent the valvemember II5 from moving more than a slight distance in either directionrelative to the outer .valve member H5.

The longitudinally extending passages I42 and I55 which are connected bymeans of the pipes I45 and I59, respectively, with the left-handcylinder chamber and right-hand cylinder chamber of the cylinder 50,respectively, are enlarged bores arranged to receive the spring actuatedvalves I43 and I56. (Fig. 9) containing the valve members I43 and I56are interconnected by means of an exhaust passage I13. It will bereadily apparent from the foregoing disclosure that fluid exhaustingfrom either of the cylinder chambers through the passage I42 or I55 andthe exhaust passage I13 exhausts through a pipe I14, through a controlvalve to be hereinafter described, to the reservoir 60. When either thevalve I43 or the valve I56 is opened to admit fluid. underpressurethrough the pipes I45 or I59 to the respective cylinder chambers, fluidcannot by-pass into the exhaust due to the fact that the valve membercuts oilthe passage of fluid through the exhaust pipe.

A control valve I80'is provided for controlling the admission of fluidunder pressure to either trol valve 55 to admit fluid under pressure tomotion of the valve member II5 by means of the manual traverse wheelwill uncover either the V-port I48a (Fig. 5) or the V-port I5l lFig. '1)depending upon the direction of rotation of the hand traverse controlwheel I24.

wheel I 24.

The flange I63 which is formed integral with.

the inner rotary valve member H4 is provided with a cut-out sector I10which is substantially I a ninety degree sector.

The outer rotary valve member I I5 which is recessed at its left-handend (Fig. 3) to receive the flange I63 of the valve member H4 isprovided with a fixed pin or stud I1I phich projects therefrom and isarranged to be engaged by the ends of the cut-out sector I10 of theflange I63, thus forming a further safety either end of the cylinder 50as controlled by the reversing or control valve 55 automatically toreciprocate the table through a predetermined stroke.

The valve I is preferably moved in timed relation with the stop andstart valve 90. As illustrated in the drawings, a link I88 is connectedbetween the right-hand ends of the valves 90 and I80 (Fig. 12) sothatwhen the stop and start valve 90 is moved to either stop or startthe hydraulic reciprocation of the table, the control valve I80 is movedtherewith to admit fluid under pressure either to the tablereciprocating mechanism or to the hand traversing mechamsm. v I

In the position of the parts asillustrated in Figs. 12 and 13, fluidunder pressure is admitted to the hydraulic table reciprocatingmechanism.

When it is desired to traverse the table by hand, the stop and startvalve 90 is shifted toward the left (Fig. 12) which serves to cut offthe port 93 to stop the exhaust of fluid from the table cylinder 50. Atthe same time, the valves .90 and I80 move toward the left (Figs. 12 and13), during which movement the valve piston I84 covers the pressure portI86 to cut oil. fluid pressure from the control valve 55 and cylinder50. As the piston I83 moves toward the left, fluid under pressurepassing through the port I into the valve chamber between valve pistonsI83 and I84 passes out through a passage I89 and a pipe I90 to themanual traverse control valve IIO. At the same time, the valve piston I82 moves toward the left so that fluid exhaustmg through the pipe I14may pass through a passage I9I into a valve chamber located between thevalve pistons I82 and I83 and out The two enlarged bores I control valve55 and admitted to the manually operable traverse control valve I I0. Bymeans of this interlocked mechanism, fluid under pressure is cut offfrom the manual traverse control valve IIO when fluid is admitted to thetable reciprocating control valve 55 and vice versa when fluid is cutoff from the table traverse control valve 56 to stop the hydraulicreciproca tion of the table, the manually operable traverse valve H0 isrendered operative.

In order to drain any oil which seeps by "the parts of the valve, an oilgroove 200 is formed between the bushing A and the rotary valve memberII5. This oil groove is connected by four radially extending passages20l with an oil groove 202 formed between the bushing C and therotatable valve member H4. The groove 202 is connected by alongitudinally extending passage 203 (Fig. 3) which connects with achamber 204 formed between the thrust collar I60 and the apron housingIIO. Oil accumulated within the chamber 204 may pass longitudinallythrough the four holes I62 which support the springs I6I and passoutwardly through drainage holes 205 formed in the apron housing IIO.Any oil draining through the passage 205 returns to the reservoir in themachine. The provision of this oil drainage passage prevents any oilleakage from being trapped within the chamber 204 and thus interferingwith the action of the friction device and actuation of the clutchparts.

The operation of this mechanism is readily apparent from the foregoingdisclosure. Assuming the parts to have been previously adjusted a workpiece is placed in position in the machine. If it is desired to grind byautomatic power traverse of the table, the valves 90 and I80 are shiftedinto the position illustrated in Figs. 12 and 13 so that fluid under,pressure is admitted to and permitted to exhaust from the table actuatedreversing or control valve 55 to reciprocate the work table 35 throughthe de-' sired table stroke. If it is desired to traverse the tableunder manual control, the lever I02 is shifted into dotted line positionI02a to shift the stop and start valve 90 together with the controlvalve I80 toward the left (Figs. 12 and 13) so as to cut off fluid underpressure from the table reciprocating valve 55 to admit fluid underpressure through the pipe I90 to the manual traverse control valve IIO.

When fluid under pressure is cut off from the table control valve 55 andadmitted throughthe port I32 into the annuar groove I33 and from theclutch members I2I.I29, to rotate the inner rotary valve member II4.

Similarly, when the stop and start valve 90 and the control valve I80are moved into the positions indicated in Figs. 12 and 13, therebycutting off fluid under pressure from the port I32, the releasedcompression of the spring I30 serves to move the inner valve member II4toward the right (Fig. 3) a short distance so as to disengage the clutchmember I29 from the clutch member I2I so that the gear I38 and shaft III'are free to rotate with the rack bar I39 during the automaticreciprocation of the table without shifting the valve parts.

Due to the compression springs I 6| holding the outer valve member- H5in frictional engagement with the flange I63 of the inner valve member,any rotary motion of the manually operable traverse wheel I24, withclutch I21, I29 disengaged will rotate the rotary valves H4 and II5together so that the relative positions of the V-ports I40a and I5Iarelative to the passages Ia and I52 will remain the same so that anytime the manual traverse mechanism is started with clutch I21, I29engaged whereby valve H4 is held stationary, only a slight rotary motionof the manual wheel I2I will be required to admit fluid and startthetable traversing movement under manual control.

When lever I02 and valves 90 and I80 are in position for a manuallycontrolled table traverse movement, a manual rotation of the traversewheel I24 in a counterclockwise direction serves to move the outerrotary valve member H5 in a counterclockwise direction so that thepassage I52 in the outer valve member II5 approaches the V-port I5I(Fig. 7) which allows passage of fluid from pipe I90, through port I32,groove I33, passage I50, V-port I5I, passage I54 and longitudinalpassage I55, past the valve I56 (Fig. 9), and out through the pipe I59into the cylinder chamber I0 at the right-hand end of the cylinder tocause the piston 5| and table 35 to move toward the left. As the tablestarts moving. toward the left, the rack bar I39 rotates the gear I38,also in a counterclockwise direction (as viewed from the front of themachine base) to cause a counterclockwise movethere into thelongitudinally extending passage I34, the pressure within thesepassages, acting upon the stationary piston I3I, produces an endwisemovement of the inner valve member II4 toward the left (Fig. 3) whichserves to move the clutch member I29 into engagement with the clutchmember I21 against the compression of thespring I30, so that when thegear I38 is rotated by' the table rack I39, this rotary motion will betransmitted through the shaft III,

ment of the inner valve member II4 so that the V-port I5I tends to closethe passage I52. In other words, when the outer valve member H5 isstarted rotating in a counterclockwise direction and fluid is admittedto start the table movement-the table movement rotates the inner valvemember H4 in the same direction. Thus the inner valve member II4 tendsto catch up with the outer valve member H5 and in this manner the speedof rotation of the manually operable traverse wheel I24 will determinethe speed of the manually controlled traverse of the table.

0 Similarly, if the manually operable traverse wheel I24 is turned in aclockwise direction (looking from the front of the machine), a clockwisemovement is transmitted to the outer valve member II 5 so that thepassage I4Ia in the outer valve member tends to approach and uncover aV-port I40a. in th inner valve and member 4..

When the passage I4Ia opens the V-port- I40a, fluid under pressure isadmitted through the annular groove MI in the periphery of the outervalve member II5, through the passage I42, the valve I43, the port I44,and the pipe I45, into the cylinder chamber II at the left-hand end ofthe cylinder 50 to cause the piston 5| and table 35 to move toward theright (Fig. 4). Movement of the table 35 toward the right operatesthrough the rack bar I39 to rotate the gear I38 in a clockwise directionwhich in turn rotates the inner valve member H4 also in a clockwisedirection so that the V-port I la tends to move in the same direction asthe passage Illa or, in other words, the inner valve member I I4 rotatesso as to catch up with the rotation of the outer valve member H5. Inthis manner, the speed of rotation of the manually operable traversewheel I24 will govern the speed of manual traverse of the table 35toward the right. I

It will thus be seen that there has been provided by this inventionapparatus in which the various objects hereinabove set forth togetherwith many thoroughly practical advantages are successfully achieved. Asmany possible embodiments may be made of the above invention and as manychanges might be made in the embodiment above set forth, it is to beunderstood that all matter hereinbefore set-forth or shownoperativelyconnected with a source of fluid under pressure, a clutch between saidshaft and valve member whereby said shaft may be connected to rotatesaid valve member, means including fluid pressure connections withinsaid valve to actuate said clutch, a second valve membersurrounding thefirst valve member and rotatably supported thereon, and means includinga manually operable hand wheel and gearing to rotate said second valvemember relative to the first valve member, said second valve,member'being provided with ports and passages to convey fluid underpressure from the first valve member to either end of a table cylinderdepending upon the direction of rotation of the hand wheel.

2. In a grinding machine having a longitudinally traversable table and arack bar thereon and a piston and cylinder operatively connectedtherewith, a hand traverse apron therefor comprising a rotatable shaft,a gear on said shaft which is arranged to mesh with the table rack, arotatable valve member surrounding said shaft and rotatably supportedthereon, means including a clutch to connect said shaft with said valvemember to rotate the valve member, a spring normally to hold said clutchdisengaged, a source of fluid pressure operatively connected withpassages in said valve member, said fluid pressure within said valvemember serving to engage said clutch, a second valve member surroundingand rotatably supported on the first valve member, said second valvemember being arranged to receive fluid under pressure from the firstvalve member and convey it in either one of two directions to either endof said table cylinder depending upon its direction of rotation, andmeans including a manually operable hand wheel to rotate said secondvalve member, said parts being arranged so that the rate of rotation ofthe manually operable hand wheel determines the rate of travers ingmovement of the grinding machine table.

3. A manually operable table traverse mechanism for a grinding machinehaving a longitudinally reciprocable table, a rack bar depending fromsaid table, a fluid'pressure system including a piston and cylinderoperatively connected to traverse said table longitudinally, a fluidpressure pump, and a hand traverse apron comprising a rotatable shafthaving a gear meshing with said rack, a valve member rotatably supportedon said shaft, a clutch between said shaft and said valve member wherebythe valve member may be rotated by movement of said shaft when the tableis traversed, fluid pressure connections between said pump and saidvalve member, fluid pressure means within said valve automatically toactuate said clutch, a second valve member surrounding said first valvemember and rotatably supported thereby, said second valve member beingconnected to admit fluid under pressure to either end of said cylinder,said valve members having ports and passages which may besuccessivelybrought into alignment to admit fluid under pressure either to oneend orthe other end of said cylinder, a manually operable hand traverse wheel,and gearing connecting said wheel with said outer valve member wherebyrotation of the hand wheel serves to open one set of ports between theinner and outer valve members to admit fluid under pressure to traversethe table in one direction, said second valve being connected throughthe shaft and gear with the tablera'ck so that it is rotated in the samedirection as the outer valve member when the table starts traversing tocatch up with the movement of the manually rotated outer valve memberwhereby the speed of rotation of the manually operable traverse wheel.determines the traversing speed of the table. 7

4. In a grinding machine having a longitudinally reciprocable table,means including a piston and cylinder'operatively connected toreciprocate said second valve member, said valve members having portsand passages arranged so that the speed of rotation of the manuallyoperable hand wheel governs the speed of the manually controlledtraverse of said table, and a control valve actuated by and in timedrelation with the stop and start valve to admit fluid under pressureeither to the table actuated reversing valve or to the manually operabletraverse apron valve.

5, In a grinding machine having a longitudinally reciprocable table,means including a piston and cylinder operatively connected toreciprocate said table, a fluid pressure system including a pump and atable actuated reversing valve, a

manually operable start and stop valve in said system to control thestopping and starting of the table reciprocation, and a manuallyoperable "traverse apron comprising a rotatable valve of the manuallycontrolled traverse of said table, and a control valve actuated by andin timed relation with said stop and start valve to admit fluid pump anda table actuated reversing valve, a-

manually operable stop and start valve to control the exhaust of fluidfrom said system to stop and start the table reciprocation, and amanually operable table traverse apron comprismg a rotatable valvemember which is operatively connected to be rotated-by the tabletraversing movement, a second rotary valve member sur roundingthe firstvalve member and rotatably supported thereby, a manually operabletraverse wheel to rotate said second valve member, said valve memberhaving ports and passages arranged so that the speed of rotation of themanually operable hand wheel governs the speed of the manuallycontrolled traverse ofsaid table, anda control valve actuatedsimultaneously with the stop and start valve to admit fluid underpressure either to the table actuated reversing valve or to the manuallyoperable traverse apron valve.

' JOSEPH R. WHITTLES.

